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Aluminum 355 vs B390.0

Aluminum · grade comparison

Aluminum 355 and B390.0 are both aluminum grades. B390.0 is the stronger of the two: yield strength 240 MPa (34.8 ksi) against 180 MPa (26.1 ksi) for 355, about 33% more; tensile strength follows at 280 MPa (40.6 ksi) vs 250 MPa (36.3 ksi). In exchange, 355 is the more ductile: elongation 3% versus 1% for B390.0, and B390.0 is harder (120 HB vs 85 HB). B390.0 is stiffer (81 GPa vs 71 GPa) and B390.0 runs hotter in service (200°C vs 175°C continuous). On the shop floor, 355 machines more easily (good vs poor), 355 welds better (good vs poor), and 355 sits in a lower cost tier (budget, $) than B390.0 (standard, $$).

355Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

B390.0Choose it when strength drives the design, or when the part sees heat.

355 vs B390.0: properties

355B390.0

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

71 GPa10.3 Msi
81 GPa11.7 Msi

Shear Modulus

26.5 GPa3.8 Msi
30.5 GPa4.4 Msi

Bulk Modulus

69 GPa10 Msi
79 GPa11.5 Msi

Tensile Strength (Ultimate)

250 MPa36.3 ksi
280 MPa40.6 ksi

Yield Strength (0.2% offset)

180 MPa26.1 ksi
240 MPa34.8 ksi

Elongation at Break

3%
1%

Shear Strength

195 MPa28.3 ksi
190 MPa27.6 ksi

Fatigue Strength (Endurance Limit)

62 MPa9 ksi
140 MPa20.3 ksi

Fracture Toughness (K_IC)

20 MPa·√m18.2 ksi·√in
14 MPa·√m12.7 ksi·√in

Hardness, Brinell

85 HB
120 HB

Charpy V-Notch Impact (RT)

—
2 J1.5 ft·lbf

Same in both: Poisson's Ratio 0.33

Physical

Density and transition temperatures.

Density

2.71 g/cm³0.1 lb/in³
2.73 g/cm³0.1 lb/in³

Melting Point (Solidus)

546°C1,015 °F
507°C945 °F

Liquidus Temperature

621°C1,150 °F
650°C1,202 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

151 W/m·K87.2 BTU/hr·ft·°F
134 W/m·K77.4 BTU/hr·ft·°F

Specific Heat Capacity

963 J/kg·K0.23 BTU/lb·°F
860 J/kg·K0.21 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

22.4 µm/m·K12.4 µin/in·°F
18 µm/m·K10 µin/in·°F

Latent Heat of Fusion

389 J/g167 BTU/lb
470 J/g202 BTU/lb

Max Service Temperature (continuous)

175°C347 °F
200°C392 °F

Min Service Temperature

-196°C-321 °F
-50°C-58 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

36 % IACS
27 % IACS

Electrical Resistivity

4.8×10⁻⁸ Ω·m1.89 µΩ·in
6.4×10⁻⁸ Ω·m2.52 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.78 V
-0.76 V

Corrosion Resistance

45 / 100
35 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

62 / 100
25 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
30%

Weldability

55 / 100
20 / 100

Castability

85 / 100
80 / 100

Brazeability / Solderability

25 / 100
20 / 100

Same in both: Formability (cold) 5 / 100 · Polishability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

200 MJ/kg85,985 BTU/lb
205 MJ/kg88,134 BTU/lb

Typical Recycled Content

80%
90%

Same in both: Embodied Carbon (primary production) 12 kg CO₂/kg · Embodied Water 1,100 L/kg132 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

92 kN·m/kg
103 kN·m/kg

Specific Stiffness (E / density)

26.2 MN·m/kg
29.7 MN·m/kg

Modulus of Resilience

228 kJ/m³
356 kJ/m³

Thermal Diffusivity

57.9 mm²/s
57.1 mm²/s

Thermal Shock Resistance Index

24
26

Strength versus weight

Yield strength against density for every aluminum grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

20501002005002.22.42.62.83Density (g/cm³)Yield strength (MPa) — log scale355B390.0

Manufacturing and finishing

Capability355B390.0
CNC machiningYes—
Default condition——
Relative cost$ Budget$$ Standard
Min. machined wall0.5 mm—
Best machined surfaceRa 0.8 µm—
Anodizing Type IIYes—
CerakoteYes—
Chem Film (Alodine)Yes—
DLCYes—
E-CoatingYes—
ElectropolishingYes—
Hard Anodize Type III w/ PTFEYes—
Hard Anodizing Type IIIYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—
Powder CoatingYes—

They share 4 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Silver Plating.

355 vs B390.0 — frequently asked

Is B390.0 stronger than 355?

Yes. B390.0 has a typical yield strength of 240 MPa (34.8 ksi) against 180 MPa (26.1 ksi) for 355 — about 33% more. Tensile strength is 280 MPa (40.6 ksi) vs 250 MPa (36.3 ksi).

Which is cheaper, 355 or B390.0?

355 is the lower-cost material: it sits in the budget tier ($) while B390.0 is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, 355 or B390.0?

355. Its machinability rates good (62/100) against poor (25/100) for B390.0; for welding the order is 355 first (good, 55/100) then B390.0 (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 355 and B390.0 side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.